20th May 2024

Diagnosis

Whilst most diagnoses of sepsis are made on purely clinical grounds, the clinical diagnosis should actually be based on the patient having an infection and a sequential (Sepsis-related) Organ Failure Assessment (SOFA) score of 2 or more. There is a 2 – 25-fold increased risk of mortality in those with a score of 2 or more.  However, the complexity of the SOFA (table 1) score often precludes its use in clinical settings.

The quick SOFA. (qSOFA) was developed as an alternative bedside tool. If the patient has an infection and fulfils 2 or more of the 3 criteria (respiratory rate 22/min or greater, GCS less than 15 or systolic blood pressure 100mmHg or less), then they are at risk of poor outcomes. A score of 2 or more should prompt further investigations of organ dysfunction and escalation of therapy if required.

Systemic inflammatory response syndrome (SIRS) definitions are no longer required for the diagnosis of sepsis. This is because a significant proportion of septic patients in intensive care units may not actually fulfil the criteria despite being critically unwell.

Septic shock is a subset of sepsis with particularly profound circulatory, cellular and metabolic abnormalities with a higher risk of mortality than sepsis alone. Septic shock can be diagnosed in those with a vasopressor requirement to maintain a mean arterial pressure (MAP) of >65mmHg and a serum lactate of >2 in the absence of hypovolaemia. Septic shock has an in-hospital mortality of >40%.